820-00840?01 PPBUS_G3H Short

[jamiehorn1]

Hi all,

got a no power 820-00840.

history is that it just stopped working, no signs of any liquid, Board is perfect. I get 20v on the charger so 3V3 is OK but 0 amps being drawn and 0v on PPBUS_G3H.

i removed the fuse and get a 3.3ohm short to ground on pin 2.

looking around the only possible sign I saw was C7754 (cap for PP1V_OPC_S0) that had a solder ball by it. I removed it but same situation.

i injected voltage at 5v into pin 2 but no amp draw and definitely nothing hot.

any ideas?

thanks

 

[JohnB8812]

Remove CPU heat sink at 3.3 ohms to ground something must get hot. Could very well be the CPU. Inspect closely to all caps as well.

 

[2informaticos]

Why people still inject tension without basic tests???
5V could went to CPU and killed it.

Any big coil has the same value to ground as PPBUS_G3H?

 

[jamiehorn1]

All big coils are measuring in kohms except CPU VCORE which is around 3ohm. Even with heat sink removed still nothing hot.
Sounding like a dead CPU, will take note on injecting voltage above 2 for PPBUS

 

[JohnB8812]

In this case, I?ve seen many many dead CPUs on the newer USBC models where PPBUS is shorted in the die of the PCH. So it doesn?t surprise me one bit if that?s what heats first here

 

[2informaticos]

At least one high-side MOSFET from CPU power supplies is shorted.
You've injected 5V directly into CPU; it is trash now.